News Articles | 14 September 2018

Earlier this month both tunnel boring machines (TBMs) reached another milestone, having now built a third of the entire length of the tunnels between Forrestfield and Bayswater Junction.

As a reward, TBM Grace has been equipped with a number of new cutterhead teeth and TBM Sandy will undergo the same treatment in the coming weeks.

With the machines now tunnelling between Airport Central and Redcliffe Stations, tunnel one has been closed between Forrestfield and the Airport to allow works to start on two new cross passages. All six multi-service vehicles are using the one tunnel, changing lanes at Airport Central Station to continue supplying segments to both TBMs.

To date, over 18,000 segments have been installed. 

Bayswater now home to WA's longest mural

The large retaining wall built adjacent to Railway Parade to support the temporary Midland Line has been turned into a piece of art thanks to PTA's Right Track program.

Perth urban artist Drew Straker, in conjunction with 75 up-and-coming junior artists, completed the work of art inspired by native animals and WA landscapes. The mural, 500m in length, is the longest of its kind in WA and one of the longest in the Southern Hemisphere.

Nearby, excavation of the 400m long dive structure, which will form the entry/exit point to the tunnels for trains, is well underway and to date more than 30,000T of material has been removed. The surplus Bassendean Sand, which can be found up to a depth of eight metres, is being transported to Forrestfield where it is used to backfill the station’s retaining wall. It is expected that 90,000T of material will be reused at Forrestfield by the end of the year, addressing a key component of the project’s sustainability program.

Finally, with micro-tunnelling for the main drain works now complete, a section of Whatley Crescent has been reopened to motorists and works will now focus on rehabilitation of the area.

Multi-deck car park plans for Forrestfield 

As announced by Transport Minister Rita Saffioti on September 11, plans for parking at Forrestfield Station have been adjusted with a multi-deck car park factored in within the station precinct. Moving away from the at-grade car park design will release eight hectares of land to create more development opportunities close to public transport. Find out more here.

In a bid to unite the divided construction site at Forrestfield (dive structure, stowage area construction and station works to the west – infrastructure vital to TBM operations to the east), a section of Dundas Road has been realigned and is now open. The road changes will allow backfilling of the station retaining wall to continue.

At the southern end of the Forrestfield Station works on the stowage area are progressing well. Stowage foundations and rail embankments are being prepared and utilities installed. Pouring of the platform sections has commenced with eight out of 32 completed.

As per Airport Central Station, the tunnel entry and exit at the Forrestfield dive structure have been fitted with sealing ring beams and waterproofing injections will commence later this month.

Redcliffe concrete pours in full swing

Three of nine concrete pours required to construct the base slab at Redcliffe Station have now been completed. 

Each pour takes around seven hours to complete and is continuously supplied by up to 14 concrete trucks. Each truck makes approximately eight trips over the course of the pour, delivering up to 650 cubic metres of concrete.

After an initial seven days of wet curing of each 1.5m deep section of the base slab, an additional 56 days are needed to complete the process.

Pours are time-critical and, once started, must continue until finished. A schedule of pours can be found on the Redcliffe Community Zone page, with the remaining six pours to be completed by mid-October.

Columns main focus at Airport Central Station

Infrastructure works at Airport Central Station continue with the construction of columns to support the different levels within the station box. 

Stair shafts spanning between the elevated walkway and concourse levels are almost completed following the installation of precast stair flights.

Up next on the schedule are ring beams for the eastern end of the station box. These are circular concrete structures connecting the tunnel segments and diaphragm walls, providing a waterproof seal at the tunnel entry and exit.

Emergency egress shafts progressing well

Given the length of the tunnels, additional infrastructure is required between the stations to allow safe egress to the ground level in the event of an emergency, and access to the tunnels for maintenance. As such, 12 cross passages and three emergency egress shafts (EES) will be built along the alignment. 

The permanent concrete between the tunnels and the EES near Abernethy Road has been poured, and focus will now shift to construction of the staircase, lift shaft and ancillary building.

At the Airport West EES construction of the base slab is scheduled for September, followed by trenching works to allow installation of services.

After completing the capping beam for the Wright Crescent EES in Bayswater, excavation of the 2500T of soil is underway within the 9m diameter shaft.

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